U.S. President Donald Trump’s special envoy Keith Kellogg said in Kyiv on Monday that officials are “working very, very hard” on efforts to end the three-year war between Russia and Ukraine, as a lack of progress fuels doubts about whether a peace settlement could be on the horizon.

Officials are “hoping to get to a position where, in the near term, we have, with a lack of a better term, security guarantees” that address Ukraine’s fears of another invasion by Russia in the future, Kellogg said.

“That’s a work in progress,” Kellogg said of the potential security guarantees after attending Ukraine’s annual National Prayer Breakfast along with politicians, business leaders and diplomats.

A week ago, Trump said he had set in motion arrangements for direct peace talks between Russian President Vladimir Putin and Zelenskyy.

But Russian officials have signaled that such a summit won’t happen any time soon.

Trump said Friday he expects to decide on next steps in two weeks if direct talks aren’t scheduled.